GaneshScience: LIST OF HEAVY ELEMENTS.: custom toolbar custom toolbar Thetransuranium elements(also known astransuranic elements) are the chemical elementswith atomic ...
Thetransuranium elements(also known astransuranic elements) are the chemical elementswith atomic numbersgreater than 92 (the atomic number of uranium). All of these elements are unstable and decay radioactivelyinto other elements.
Overview
Periodic table with elements colored according to the half-life of their most stable isotope.
Elements which contain at least one stable isotope.
Slightly radioactive elements: the most stable isotope is very long-lived, with a half-life of over four million years.
Significantly radioactive elements: the most stable isotope has half-life between 800 and 34,000 years.
Radioactive elements: the most stable isotope has half-life between one day and 103 years.
Highly radioactive elements: the most stable isotope has half-life between several minutes and one day.
Extremely radioactive elements: the most stable isotope has half-life less than several minutes.
Of the elements with atomic numbers 1 to 92, all can be found in nature, having stable (such as hydrogen), or very long half-life(such as uranium) isotopes, or are created as common products of the decay of uranium and thorium (such as radon) — only technetium, of the elements below uranium, was man-made for its discoveryin 1936.
All of the elements with higher atomic numbers, however, have been first discovered in the laboratory, with neptunium, plutonium, americium, curium, berkeliumand californiumlater also discovered in nature. They are all radioactive, with a half-lifemuch shorter than the age of the Earth, so any atoms of these elements, if they ever were present at the Earth's formation, have long since decayed. Trace amounts of these six elements form in some uranium-rich rock, and small amounts are produced during atmospheric tests of atomic weapons. The Np, Pu, Am, Cm, Bk, and Cf are generated from neutron capturein uranium ore with subsequent beta decays(e.g. 238 U+ n→ 239 U→ 239 Np→ 239 Pu).
Transuranic elements can be artificially generated synthetic elements, via nuclear reactorsor particle accelerators. The half lives of these elements show a general trend of decreasing as atomic numbers increase. There are exceptions, however, including dubniumand several isotopes of curium. Further anomalous elements in this series have been predicted by Glenn T. Seaborg, and are categorised as the “ island of stability.” [ 1 ]
Heavy transuranic elements are difficult and expensive to produce, and their prices increase rapidly with atomic number. As of 2008, weapons-grade plutonium cost around $4,000/gram, [ 2 ]and californiumcost $60,000,000/gram. [ 3 ]Due to production difficulties, none of the elements beyond californium have industrial applications,[ citation needed]and of them, only einsteiniumhas ever been produced in macroscopic quantities. [ 4 ]
Transuranic elements that have not been discovered, or have been discovered but are not yet officially named, use IUPAC's systematic element names. The naming of transuranic elements may be a source of controversy.
Discovery and naming of transuranium elements
So far, essentially all the transuranium elements have been produced at three laboratories:
*.The Radiation Laboratory (now Lawrence Berkeley National Laboratory) at the University of California, Berkeley, led principally by Edwin McMillan, Glenn Seaborg, and Albert Ghiorso, during 1945-1974:
*.93. neptunium, Np, named after the planet Neptune, as it follows uraniumand Neptune follows Uranusin the planetary sequence(1940).
*.94. plutonium, Pu, named after the dwarf planet Pluto, following the same naming rule as it follows neptunium and Pluto follows Neptune in the pre-2006 planetary sequence (1940).
*.95. americium, Am, named because it is an analog to europium, and so was named after the continent where it was first produced (1944).
*.96. curium, Cm, named after Pierreand Marie Curie, famous scientists who separated out the first radioactiveelements (1944).
GaneshScience: Feedbacks to blogger.: custom toolbar custom toolbar I like blogging very much thanks to blogger. I really want to appriciete blogger. Thank you very ...
GaneshScience: Do u know ?: custom toolbar custom toolbar ¤The harrier jump jet can take off vertically (i.e without needing a runway) ¤The fuel in a jumbo ...
Biology deals with the study of the many varieties of living organisms. Clockwise from top left: Salmonella typhimurium(a type of bacteria), Phascolarctos cinereus(koala), Athyrium filix-femina(common lady-fern), Amanita muscaria(fly agaric, a toxic toadstool), Agalychnis callidryas(red-eyed tree frog) and Brachypelma smithi(Mexican Red-kneed Tarantula)
Biologyis a natural scienceconcerned with the study of lifeand living organisms, including their structure, function, growth, evolution, distribution, and taxonomy. [ 1 ]Modern biology is a vast and eclectic field, composed of many branches and subdisciplines. However, despite the broad scope of biology, there are certain general and unifying concepts within it that govern all study and research, consolidating it into single, coherent fields. In general, biology recognizes the cellas the basic unit of life, genesas the basic unit of heredity, and evolutionas the engine that propels the synthesis and creation of new species. It is also understood today that all organisms survive by consuming and transforming energyand by regulatingtheir internal environment to maintain a stable and vital condition.
Subdisciplines of biology are defined by the scale at which organisms are studied, the kinds of organisms studied, and the methods used to study them: Biochemistryexamines the rudimentary chemistry of life; molecular biologystudies the complex interactions among biological molecules; botanystudies the biology of plants; cellular biologyexamines the basic building-block of all life, the cell; physiologyexamines the physical and chemical functions of tissues, organs, and organ systemsof an organism; evolutionary biologyexamines the processesthat produced the diversity of life; and ecologyexamines how organisms interact in their environment.
GaneshScience: Genes: Ageneis the molecular unit of heredityof a living organism. It is used extensively by the scientific community as a name given to some str...
Ageneis the molecular unit of heredityof a living organism. It is used extensively by the scientific community as a name given to some stretches of deoxyribonucleic acids(DNA) and ribonucleic acids(RNA) that code for a polypeptideor for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains. Genes hold the information to build and maintain an organism's cellsand pass genetic traitsto offspring. All organisms have genes corresponding to various biological traits, some of which are instantly visible, such as eye coloror number of limbs, and some of which are not, such as blood type, increased risk for specific diseases, or the thousands of basic biochemicalprocesses that comprise life. The wordgeneis derived from the Greekwordgenesismeaning "birth", orgenosmeaning "origin" (see pangenesis).
The chemical structure of a four-base fragment of a DNA double helix.
A modern working definition of a gene is "a locatable regionof genomicsequence, corresponding to a unit of inheritance, which is associated with regulatory regions, transcribed regions, and or other functional sequence regions". [ 1 ] [ 2 ]Colloquial usage of the termgene(e.g. "good genes", "hair color gene") may actually refer to an allele: ageneis the basic instruction— a sequence of nucleic acids (DNA or, in the case of certain virusesRNA), while analleleis one variant of that gene. Thus, when the mainstream press refers to "having" a "gene" for a specific trait, this is customarily inaccurate. In most cases, all people would have a gene for the trait in question, although certain people will have a specific allele of that gene, which results in the trait variant. Further, genes code for proteins, which might result in identifiable traits, but it is the gene ( genotype), not the trait ( phenotype), which is inherited.
Big genes are a class of genes whose nuclear transcriptspans 500 kb (1kb = 1,000 base pairs) or more of chromosomal DNA. The largest of the big genes is the gene for dystrophin, which spans 2.3 Mb. Many big genes have modestly sized mRNAs; the exons encodingthese RNAstypically encompass about 1% of the total chromosomal gene region in which they occur.
GaneshScience: Nuclear power: Nuclear power, ornuclear energy, is the use of exothermic nuclear processes, [ 1 ]to generate useful heatand electricity. The term inclu...
